Introduction to the Immune system pt II

Question 1

What parts of the innate immune system do we expect to be functioning within the first 6 hours of an infection?

Answer 1

phagocytes, complement, physical barriers

Question 2

What parts of the innate immune system do we expect to be functioning within the first 12 hours of an infection?

Answer 2

phagocytes, complement, physical barriers, and NK cells

Question 3

How long does it take for lymphocytes to undergo proliferation in response to an APC or a pathogen?

Answer 3

4 days

Question 4

How long does it take for antibodies and effector cells to be produced by effector cells?

Answer 4

around 7 days

Question 5

How long does an adaptive immune response take?

Answer 5

from days to weeks?

Question 6

Humoral response is

Answer 6

extracellular and uses Abs

Question 7

Cell mediate response is

Answer 7

intracellular and uses T cell-APC interactions

Question 8

“generative lymphoid organs” include

Answer 8

thymus and bone marrow

Question 9

“peripheral lymphoid organs” include

Answer 9

lymph nodes, spleen, mucosal/cutaneous lymphoid tissues

Question 10

All B lymphocytes develop from ____ during ____ of the ____

Answer 10

precursors formed allthrough the life of the person

Question 11

All T lymphocytes are generated in the ____ during the _____

Answer 11

thymus during the fetal stage

Question 12

BCRs are what, and what do they recognize?

Answer 12

B cell receptors

they recognize carbohydrates, proteins, lipids, and nucleic acids

Question 13

Plasma cells do what

Answer 13

effector cells of B cell lineage: produce antibodies

Question 14

Abs are secreted where?

Answer 14

into circulation and in the mucosal tissue

Question 15

what do Abs do?

Answer 15

neutralize and eliminate extracellular microbes and microbial toxins

Question 16

name the “3 big” things about Abs

Answer 16

they neutralize, eliminate, immobilize pathogens

Question 17

What do T cell’s recognize, and with what?

Answer 17

peptides in primary formation only

Question 18

What are the two kinds of T cells and what are their traits?

Answer 18

Helper T cells (which express CD4)

Question 19

What do helper T cells do?

Answer 19

they can activate macrophages, initiate inflammation, stimulate proliferation/differentiation of B/T lymphocytes

Question 20

What do cytotoxic T cells do?

Answer 20

directly kill infected cells

Question 21

How do T cells activate macs?

Answer 21

IFN-gamma

Question 22

What are the “3” steps involved in antigen capture for an APC?

Answer 22

1) capture
2) processing
3) presenting Ags

Question 23

Professional APCs include

Answer 23

MOs, dendritic cells, B cells

Question 24

Non-professional APCs include

Answer 24

all nucleated cells in the body except the above listed

Question 25

What do professional APCs activate?

Answer 25

both helper T cells and cytotoxic lymphocytes

Question 26

what do non-professional APCs activate?

Answer 26

only cytotoxic lymphocytes

Question 27

what happens to the non-professional APC after infection and interaction with a CTL?

Answer 27

they are directly destroyed

Question 28

Blood born versus epithelial pathogens

Answer 28

epithelial pathogens are phagocytised in the epithelia, where they are then transported to a lymph node to display to a T cell blood born pathogens are carried through the circulatory system to the spleen to be presented

Question 29

the lymph node captures antigens from the

Answer 29

epithelium and connective tissues

Question 30

the spleen captures antigens from the

Answer 30

blood

Question 31

passage of an Ag in the lymph through/to the lymph node

Answer 31

APC cell (dendrites) carries Ag through lymph system through Afferent lymphatic vessels to the T cell zones, where they present to T cells free-floating Ags are delivered to the B cell zones in the cortex

Question 32

Two ways Ag can be delivered to the lymph node: free floating and via dendrite explain

Answer 32

APCs deliver Ag to T cells | free floating Ags delivered to B cells

Question 33

PALs consist of what cells

Answer 33

BOTH the immediate T cells around the artery and the B cells a little further out

Question 34

white pulp =

Answer 34

T cells surrounding artery and lymphoid follicles

Question 35

MHC complexes: what are they

Answer 35

I and II ``` class I MHC is expressed by all nonprofessional APCs class II MHC is expressed by all professional APCs ```

Question 36

who recognizes which mhc class?

Answer 36

Th cells express CD4; rec MHC II and MHC 1 | CTLs express CD; rec MHC 1

Question 37

which cells express MHC, BCRs, and TCRs?

Answer 37

MO and DCs express MHC class I and II T cells express class I MHC but not class II or BCRs B cells express both MHC I and II, BCR but no TCR Granulocytes express Class I MHC Erythrocytes do express anything

Question 38

the TCR has two grooves: what for?

Answer 38

one is for the polymorphic region of the MHC molecule | one is for the residue of the peptide being presented

Question 39

the MHC has one pocket, one structural peg, and an informal peg

Answer 39

the informal is the peptide being carried to the TCR the formal is a polymorphic region that interacts with the TCR there is a binding groove for the "anchoring" residue

Question 40

peptides bind to MHC molecules how?

Answer 40

by anchor residues

Question 41

Class I MHC Ag presentation pathway what kinds of ags to whom are they presented NB! who expresses them

Answer 41

Intracellular pathogen molecules CTLs "only" MHC I will never be "empty" of an Ag if expressed all nucleated non-professional cells

Question 42

Class II MHC Ag presentation pathway

Answer 42

only expressed by professional APCs | MOs, dendritic cells, B cells

Question 43

microbial Ags are taken up by phagocytosis and endocytosis. who does what

Answer 43

macrophages phagocytize; B cells and dendritics take up via endocytosis

Question 44

to whom are Ag-loaded MHC II cells taken?

Answer 44

Th

Question 45

Phases of Adaptive Response (5)

Answer 45

1) Ag recognition --> Ag recognized 2) Lymphocyte activation --> clonal expansion AND differentiation into effector T lymphocytes/Plasma cells 3) Effector phase --> humoral/cell mediate response --> elimination of antigens 4) Decline (homeostasis) --> apoptosis 5) memory --> surviving cells

Question 46

how does the immune response decline?

Answer 46

as Ag presence declines, apoptosis of effectors increases